Assessment for the Incidence of Number of Subcultures on Genotype Stability for In Vitro Plantlets of Yam (Dioscorea spp.) Using RAPD Markers.

Abstract

The impact of the number of subcultures on the stability of yam genotype maintained in in vitro genebank was investigated. Six accessions of yam (Ala, Bagri Kogan, Kokoro, Sossou, and Tankpanou), belonging to the complex Dioscorea cayenensis- rotundata were initiated on free-hormone MS medium and were micropropagated each four months during five subcultures. DNA was extracted both from mother plant and plantlets provided from the subcultures for each accession and was exhibited Random Amplified Polymorphic DNA (RAPD) analysis using four selected primers to detect somaclonal variation. No phenotypic variation was observed during the fifth subcultures. From the RAPD analysis of both mother plants and in vitro plantlets, no significant variation of DNA profiles was observed with the highest of the coefficient of similarity (85% to 100%) for all accessions, thus ensuring the genetic stability of the plants and regeneration of true to type plants for at least five subcultures.